Where is Ground Connection"B" ? Options

[kenshapiro2002]

Where is the ground numbered #83 (Ground connection "B") on a 1970 914? It's not the one in the rear trunk, and not the one by each headlight. It's the one that grounds all the dash switches, door switches, fan and heater switch, etc.

[kenshapiro2002]

OK...pin 31 (ground) is excellent. Pin 49 is getting 12 volts and it's not fluctuating with the different loads. This seems wrong though...as soon as I turn on the ignition, the flasher relay is getting 12 volts, but it's not making any sound. I guess it's quiet until it gets a signal from the flashers through one of the other pins?

[kenshapiro2002]

Yeah...after looking at the schematic, I think it's normal for the red lead to be "hot" as soon as the ignition is turned on. Seems the flasher relay is good as is its ground and power source. My rookie guess is till that something else is wrong and is powering up the relay through the ground wire.

Significant evidence seems to me to be:

When I took delivery of the car, the problem did not exist. The brake light switch on the brake pedal was so far out of adjustment that no brake lights went on. I fixed that. Unplugging it does not eleviate my current problem. The handbrake switch was screwed up and did not work either. I freed that up now and it works. There was no bulb in the multi gauge for the handbrake light / brake failure. A PO had[i] to have removed it because of some electrical glitch that had it on all the time.

When I took delivery of the car, the turn signal indicators were screwy. One of them would flash correctly (can't remember which one), and the other would start to flash on its correct side, and then both arrows would start to flash at the same time.

OK...pin 31 (ground) is excellent. Pin 49 is getting 12 volts and it's not fluctuating with the different loads. This seems wrong though...as soon as I turn on the ignition, the flasher relay is getting 12 volts, but it's not making any sound. I guess it's quiet until it gets a signal from the flashers through one of the other pins?

[Spoke]

When I took delivery of the car, the turn signal indicators were screwy. One of them would flash correctly (can't remember which one), and the other would start to flash on its correct side, and then both arrows would start to flash at the same time.

When both flashed together, were they 1/2 brightness? This seems to be a common failure of the flasher relay. Look at the schematic and imagine what happens if the center connection of the indicator lights doesn't connect to pin 49 as the schematic shows. If the relay on pin K doesn't close when the turn signals are on, both lamps will light and will split the voltage 6v across each lamp.

Like Andy mentioned, if the center connection of the indicator lamps is disconnected from pin K and connected to ground, then each indicator will flash as desired. The bulbs will have to be reversed in their sockets since the right indicator is connected to the left bulbs and the left indicator to the right bulbs.

My rookie guess is till that something else is wrong and is powering up the relay through the ground wire.

You can check this in 2 ways. Disconnect the flasher relay and measure resistance (ohms) from the brown wire to chassis. This measurement should show less than 1 ohm.

Second way is to measure voltage on the brown wire to chassis when power is applied to loads like brake lights, radio, wipers, etc. This measurement should show zero voltage if the wire is ok.

Do this test: Remove the flasher relay and measure resistance (ohms) to chassis on the wire connected to pin 49a. With 4-way flashers and turn signals off, you should measure infinite ohms (no deflection on an analog needle) or the same reading on a digital multimeter when measuring ohms and the probes are not touching anything.

If you measure resistance, something is pulling down on the relay and could be causing it to chatter.